Texas flooding updates: Over 130 dead as flash flood threat increases in Texas

After touring the flood zone, President Donald Trump took part in a roundtable event with first responders and local officials at the Hill Country Youth Event Center.

"The first lady and I are here in Texas to express the love and support and the anguish of our entire nation in the aftermath of this really horrific and deadly flood. Nobody has any idea how and why a thing like this could happen," Trump said as he delivered opening remarks.

"We mourn for every single life that was swept away in the flood, and we pray for the families that are left behind. It's amazing, the incredible spirit from those families," he said.

Trump went on to thank first responders who jumped in to respond immediately and those that are assisting in the search for those still missing.

"The people that are doing it are unbelievable people. ... You couldn't get better people than this," Trump said.

-ABC News' Alexandra Hutzler

President Donald Trump is on the ground in Texas to witness the destruction from the floods.

Trump and Gov. Greg Abbott met with first responders on the scene before Trump's roundtable event with local officials.

Trump is joined on his trip by Ted Cruz and John Cornyn, the state's two Republican senators.

The risk of the catastrophic flooding that struck Texas Hill Country as people slept on July 4 and left at least 120 dead was potentially underestimated by federal authorities, according to an ABC News analysis of Federal Emergency Management Agency data, satellite imagery and risk modeling.

Some of the youth camps and recreational areas most devastated by the extreme weather were established on land designated by the FEMA as "special flood hazard areas" or in the river's floodway, making them especially vulnerable to the July 4 flash floods that exceeded some federal estimates for a worst-case scenario.

At some points, water extended for hundreds of feet outside the Guadalupe River's banks and beyond FEMA estimates, according to satellite data. First Street, a risk modeling company, told ABC News that the company believes that more than double the 8 million homes nationwide that are designated by FEMA to be in flood zones are actually at risk, finding that government models are outdated and fail to consider extreme weather events.

Read more here.

-ABC News' Kerem Inal, Peter Charalambous and Gaby Vinick

President Donald Trump travels to Texas on Friday amid growing questions about how local officials responded to the devastating floods, as well as questions about the federal response -- including FEMA's fate -- that he has so far avoided.

Trump's visit comes a week after heavy rainfall caused the Guadalupe River in Kerr County to rise 26 feet in less than an hour, killing at least 121, including dozens of children at the nearby Christian summer camp, Camp Mystic.

He and first lady Melania Trump will visit flood-affected areas, according to a statement from the first lady's office.

Read more here.

-ABC News' Alexandra Hutzler